This paper described the liquid flow battery system with graphite felt electrode and a single electrolyte, lead (II) in methanesulfonic acid. The kinetics and cyclic voltammetry behavior of graphite felt electrode and effects of modifying graphite felt on them were studied. The results show that the dynamic characteristics of graphite felt electrode in strong polarization region was better than that in weak polarization region. The oxidation and reduction peak potentials were basically unchanged with the increase of cycle number, and the redox reversibility of the graphite felt electrode was good. The graphite felts soaked by methanesulfonic acid (99.8%) hadmore excellent cyclic voltammertry behavior.